1. Field of the Invention
The present invention relates generally to hand tools, and more specifically to a combination tool comprising a plurality of open or box end wrenches, all pivotally connected to a common central plate or plates which serves as an extension handle for an unfolded wrench. Stop means is also provided to lock a selected wrench in a fully extended position as desired.
2. Description of the Related Art
All persons who have had occasion to work with threaded fasteners, recognize the need for a wrench or wrenches which are capable of accommodating a wide variety of sizes of hexagonal bolt heads and nuts. Essentially two alternatives have been provided in the past: Either (1) the adjustable wrench, or (2) a plurality of separate wrenches, each having a different size.
While the adjustable wrench has its place in a mechanic's tool box, it is generally not considered suitable for most work due to the lack of precision provided in such tools to allow for the adjustability. The jaws are all too easily shifted from a precise fit on the fastener, and may round off the corners of a fastener to which they are applied.
While a complete set of separate open or box end wrenches of good quality obviates the above problem, the result is more complex due to the sheer number of individual tools which must be carried. A set of metric wrenches, for example, would number approximately fifteen wrenches in order to cover all of the fastener sizes which are in more or less common use up to about one inch in diameter. And this only covers metric sizes, with fractional inch fasteners requiring another complete set of about the same quantity. Obviously, it is very easy to misplace a wrench from a set from time to time, thus adding to the expense for a mechanic to maintain a complete set of tools, meanwhile at least inconveniencing the mechanic until the missing wrench can be replaced.
Accordingly, a need will be seen for a folding wrench cluster, incorporating several commonly used sizes of open or box end wrenches in a single unit. The wrench cluster must provide for the folding of the wrenches into a relatively compact unit for storage when not in use, preferably of sufficiently small size to allow the cluster to be carried easily in a pocket. Yet, the device must provide for the extension of a selected wrench from the cluster to a practicable working length in order to provide the leverage required of such tools. Also, the cluster must provide a positive locking means when a selected wrench is extended, in order to provide sufficient rigidity for the unit in its extended state.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 1,003,997 issued on Sep. 26, 1911 to Albert Dudly, Sr., titled "Wrench," describes a folding double open end wrench unit, in which the two wrenches are secured to one another by a slip joint. When the two wrenches have been opened relative to one another, they are extended along their mutual longitudinal axis in order to lock them in an extended position. This system requires two manipulations of the device in order to first extend and then to lock the wrenches in the extended configuration, with the two manipulations being reversed for folding. Also, the Dudly, Sr. wrench configuration cannot be expanded to provide more than two wrenches in a single assembly, which would still require a relatively large number of dual wrench units. The present invention may provide any practicable number of wrenches as desired, for greater versatility.
U.S. Pat. No. 1,186,807 issued on Jun. 13, 1916 to John L. Litomy, titled "Tool," describes a multiple wrench tool wherein each of the wrenches is secured in a common holder by an elongate slot in each wrench, forming a slip joint. As in the Dudly, Sr. wrenches discussed immediately above, each of the Litomy wrenches is relatively thin, with the handle portion being as thick as the head portion of each wrench. This is a relatively light duty construction, and is not as durable as the wrench configuration of the present invention, wherein each of the wrenches has a relatively thicker head for greater strength. Moreover, Litomy provides for multiple sizes in each of his wrench heads, thus requiring each head to be relatively large in diameter and bulky.
U.S. Pat. No. 1,402,373 issued on Jan. 3, 1922 to Charles G. Palmer, titled "Combination Wrench," describes a tool having a single common handle or body portion with a plurality of wrenches secured thereto. The title "Combination Wrench" is not accurate in the present sense of the term, as all of the wrenches of the Palmer assembly are open end wrenches, rather than being a combination of an open end and closed end wrench each having the same wrench size, as the term is presently used. Palmer describes a cam type locking system to hold a selected wrench in an open position, but such a system is prone to slippage, as it does not provide a positive stop as does the extension lock of the present wrench cluster. Again, the Palmer wrenches are all relatively thin stampings offering relatively little gripping strength in the head portions, as in the other wrenches discussed above. The present wrench cluster provides wrenches having heads of sufficient thickness to provide substantial strength and durability.
U.S. Pat. No. 1,503,084 issued on Jul. 29, 1924 to Foree Bain, titled "Wrench," describes an open end wrench assembly having a generally U-shaped clamp securing all of the wrenches together pivotally at one end thereof. The clamp also serves as a locking means to prevent a selected wrench from pivoting beyond a maximally extended position, but the handle means comprises the remaining wrenches in the assembly, rather than there being a separate handle provided. Again, as in the other wrench assemblies discussed above, each of the Bain wrenches is relatively thin, offering relatively low structural strength compared to the present wrenches.
U.S. Pat. No. 2,097,361 issued on Oct. 26, 1937 to John J. Bagley, titled "Wrench," describes an assembly of flat, thin wrenches extending from each end of a flat central bar member, which is also configured as a wrench. Each of the wrenches is secured to one or the other side of the bar by a transverse hinge. As the hinge pin is in the plane of rotation of the wrenches, it serves as a lock to preclude folding of the wrenches when in use. However, the relatively thin hinge pin does not provide particularly good strength for such a purpose, in comparison to the extension locking means of the present wrench cluster. Also, the Bagley wrenches are each formed of a relatively thin, flat stamping or the like, with the problem of structural strength in such relatively thin components having been noted in each of the other devices of the related art discussed above. Moreover, the central bar of the Bagley assembly precludes complete folding of the assembly, thus precluding any particularly compact storage for the device, whereas the present folding wrench cluster may be compactly folded for carriage in a pocket or the like if desired.
U.S. Pat. No. 2,466,884 issued on Apr. 12, 1949 to Harvey W. English et al., titled "Open Ended Multiple Wrench Holder," describes a plural wrench assembly wherein each of the wrenches may be telescopingly extended from a central holder portion. No pivoting action is provided by English et al., as provided in the present invention. As in the other devices discussed above, the English et al. wrenches are each formed of relatively thin, flat stampings having comparatively little strength in the head portions.
U.S. Pat. No. 4,269,311 issued on May 26, 1981 to Jackson E. Rich, titled "Portable Hand Carried Kit For A Set Of Wrenches And The Like," describes an elongate box-like closure having a transverse pin therethrough, with a plurality of wrenches pivotally extendible from the pin when the box is opened. At least one slot extends across the end of the box when it is closed, for securing a selected wrench in the extended position for work. The box structure is relatively long, as it must provide for the complete enclosure of all of the wrenches when they are folded for storage. The same problem as discussed above is apparent with the Rich wrench assembly, in that each of the Rich wrenches is formed of a relatively thin, flat stamping offering comparatively little structural strength for providing the required torque to secure or unfasten a threaded nut or bolt. The wrenches of the present invention each have a considerably thicker head, and provide significantly greater strength.
U.S. Pat. No. 4,606,247 issued on Aug. 19, 1986 to Charles H. Graham, titled "Versatile Chained Tool Set," describes a tool comprising a series of interconnected links forming a closed loop, loosely similar to a roller chain loop. Each of the links has a wrench head formed integrally therewith, or some other tool component extending therefrom. The device is intended to fold flat when not in use, or to use the folded flat loop as a handle for an extended tool. The wrench heads are accordingly relatively thin in order to provide for compact folding, resulting in a reduction of strength in comparison to the thicker heads of the present tool.
Italian Patent Publication No. 294,821 published in June, 1936 illustrates a wrench comprising a single socket extension which is foldable along a transverse handle. Foldable handle extensions are provided at each end of the transverse handle. No multiple wrenches are apparent, and the device does not appear to be adaptable to open or box end wrenches, as provided by the present invention.
German Patent Publication No. 2,107,628 published on August 26, 1971 illustrates a foldable combination screwdriver and nut driver. The basic structure comprises a hollow stem with two arms foldably extendible therefrom to form a T in their extended positions. Each of the three components forming the T includes a socket wrench at its distal end. The stem of the T is hollow for housing a square drive shaft providing for the attachment of additional tool heads or the like thereon. While the square drive shaft provides for the removable attachment of an open end wrench head thereto, no multiple open or box end wrenches are disclosed, nor is any combination of two or more wrenches disclosed which have a common pivotal axis, as in the present folding multiple wrench cluster.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.